Lee Martin bagged a second-half brace as Gillingham came from behind to beat Portsmouth 3-1 at Fratton Park. Jamal Lowe gave Pompey a 19th-minute lead when he fired a close-range effort into the roof of the net for his seventh goal in all competitions this season.And the 23-year-old should have doubled his side's advantage just before the half-hour mark when he was in on goal but Gillingham defender Luke O'Neill got back to make a last-ditch tackle.The visitors struck back through half-time substitute Conor Wilkinson in the 48th minute after he took a touch to set himself up before curling his shot into the bottom corner.The Gills then took the lead through Martin when his free-kick managed to drift past everyone and find the back of the net.And Martin got his second and secured all three points for the away side with a spectacular goal in the 80th minute, the Gillingham captain curling the ball into the top corner from outside the area.